Cylinder for internal-combustion engines



Jan. 27, 1925. 1,524,391 C. B. DURHAM CYLINDER FOR INTERNAL COMBUSTLON ENGINES Filed Oct. 9, 1922 CADY B. DURHAM, or FLINT, MICHIGAN, Tron, or DETROIT, Mrciioaiv,

ASSIGNOR TO GENERAL MOTORS CORPORA- A CORPORATION 0F DELAWARE.

CYLINDER FOR INTERNAL-CO'MBUSTION ENGINES.

Application filed October i 10 all fr0/wm t may concern.'

Be it known that I, CADY B. DURHAM, a citizen of the United States of America, and a resident of Flint, county of Genesee, and State of Michi an, have invented certain new and useful mprovements in Cylinders for Internal-Combustion Engines, of which the following is a full, clear, concise, and exactl description, such as will enable others skilled in the art to which the invention relates to make and use the same, reference being made therein to the accompanying drawings, which form a part of this specication.

My invention relates to the manufacture of cylinders for internal combustion engines from cast metal, and is. characterized by the chilling of the inner surface thereof with which the piston moves in contact in thc completed engine. Such cylinders are coinmonly made from cast iron which metal, in

Aits ordinary form, is apt to be lacking in hardness and density, and provides an unsatisfactory surface for the piston to move over. I have found, however, that a much better wearing surface and one less likel7 to be injured when the cylinder is in use is secured if the inner surface thereof is chilled during the casting operations; the increased hardness and density produced by chilling providing a surface which, when finished to size as by grinding or otherwise, provides a surface which may be better and more eiiiciently lubricated, as well also as a surface with which the piston is less likely to seize should the supply of lubricant thereto be unduly reduced or interrupted; and 'a wearing surface which in general is more perfect than has heretofore been the case. Pistons made from aluminum or an alloy including aluminum as its principal ingredient, such as are in extensive use at the present time, are found work much better with such a chilled surface or cylinder wall than with an unchilled cast iron surface; and a cylinder made in accordance with my invention has enhanced wearing qualities because of the increased hardness and density of cylinder wall resulting from the chilling of the material thereof during the casting operation.

My invent-ion is regarded as including certain improvements in and relating to the art, method or process of producing internal combustion engine cylinders from cast 9, 1922. serial No. 593,306.

metal, as well also as in a core used in the casting thereof and in the cylinder produced in accordance with suoli method and by the use of said core; and is so claimed in the claims at the end of this specification wherein the distinguishing features of my invention are particularly pointed out.

In the drawing accompanying and forming a part of this specification:

Figure l-is a plan view showing a mold used in producing an internal combustion engine cylinder block made up of two cylinders in accordance with my invention, the upper portion of the mold being omitted.

Figure 2 is a view showing the lower mold section shown in Figure l in section upon a vertical pla-ne extending along the axis of one of the cylinders, the core being shown in side elevation.

Figure 3 is a viewvshowing a section upon a transverse vertical plane indicated by the line 3, 3, Figure l. i

Figure 4 is a view showing a transverse section of one of the two parts of a core box used in .making the core contemplated in my invention.

Referring now to the drawing, the refer- Y ence numeral 5 designates a lower mold section comprising a flask member or frame filled with sand and the upper surface of which has (by the use of a suitable pat tern and during suitable filling and ramming operations) been given a contour corresponding with that of one half the ex ternal configuration of the cylinder block to be produced, as is usual in molding operations. The upper flask section and corresponding mold part is not shown as my invention is not concerned with the mold sections whereby tlie proper external form is imparted to the cylinder block produced in accordance with my invention. i

Supported within the mold cavity corre sponding with the external contour of the cylinder block produced is a suitable core comprising cylindrical portions 7. 7 which provide the bores of the two cylinders of the block, and other portions 8 (not involved in my invention) whereby the inlet, the exhaust and spark plug passages of the block are provided. The core is supported from its ends by lugs 9, 9 fit-ting within recesses provided in the external mold sections by core prints upon the cylinder block pattern, or otherwise, in accordance with schemes 'cast.-iron,- steel 'Kor Y equivalent material.. lcurved 1n crosssection so as to correspond with the curvature oli theinner surfaces ot the cylinders to be produced; said plates being spacedfslightly apart trom one another and disposed circumterentially ot the cores Aso as to provide substantially continuons Achill 'members V or devices with which the molten metal contacts as it is poured into the mold. These *clnlling members are shown as ofa.l length corresponding approxivmately'witlr'that of the portions of the cylinders over which the pistons move in the=comp'leted engine, as those parts ot the interior of the cylinders with lwhich the` pistons Contact should `be oi uniform hard- Vness, texture and composition tliroughout;

although the' inner vsurfaces of the combustion chambers and the lower ends et the cylinders not uncovered by the pistons such portions --being beyond the limitsof travel. vof the pistons, are preferably left unehilled:

such end beingattained by making the ehill ingmembersshorter than the interior Vbores of the cylinders, as will be appreciated.

luf-forming the corefthe. backs or inner faces of thel metallic plates l2 are preferablyvr Vcoated* with a suitablepaste or cement to secure a more perfect iointbetween them and the 'sandy from which the core is 'foi-med. and then placed in a suitable vcore box indicated by the numeral 13 in Figurelf; the

plates being' spaced properly apart vby lugs Minthebottom of the core box. The core boX is then lilledv with core sand and dried and baked, thefcomplete core beingniade up of two similar parts cemented together as is usual in core making practice. The sidil edges of the chills`l2 are preferably `beveled as shown, and the longitudinal `grooves between adjacent edges of the plates as well as the holes. left. byv thelugs 14 upon removing the core sections from the core box will be filled in with core sand in order to provide a smooth exterior core sui-tace. as will be understood.

Obviously the chill plates ma y be anchored to the body of the core by simply embeddiml.' them or portions ot them therein, instead ot by using a cement or adhesive for that purpose, and, while I have disclosed my invention as employed. in the production ol' a cji'linder block having two cylinders the saine is equally applicable tor the prodnctic-n ol cylinder blocks having more than two individual cylinders, or for the pro` duction of single cylinders for use in intcrnal combustion engines.

Having thus described and explained my invention, l. claim and desire to secure by Letters Patent:

l. il sand core for use in formino an internal combustion engine cylinder lroni cast metal. said core having chilling means adapted to chill the internal `surface ot a cylinder produced by the use ot said core.

A sand core for use in producing ai: internal combustion 'enginel cylinder from cast metal, said core comprising a. cy1indri cal portion having one ormore curved metallic platesadapted to chill the interior of' a cylinder tornied by the use of said core.

A sand core Yfor use in making an internal combustion engine cylinder from cast metal,r said core comprising a cylindrical portion. .and a plurality7 of segmental metallic plates etendingalong and spaced circumfercntially about and embedded ,in said. cylindricalcore and adapted to chill the internal surface of a cylinder produced ln' the use ot said Core.

ln testimony whereof I allix my sign at nrc.

n CADY B. DURHAM. 

